In the process of shipping one or more articles, products or other objects in a container, such as boxes/cartons, from one location to another, a protective packaging material or other type of dunnage material is typically placed in the shipping container to fill any voids and/or to cushion the item during the shipping process. Some commonly used dunnage materials are plastic foam peanuts, plastic bubble pack, air bags and converted paper dunnage material.
In many instances, the dunnage material is used to top-fill a container in which one or more objects have been placed, thereby to fill any remaining void in the container and thus prevent or minimize any shifting movement of the object or objects in the container during shipment. If an automated dispenser is used to supply dunnage material for filling the box, perhaps the most prevalent practice today is for the operator of the dispenser to observe the container as it is being filled with dunnage material and stop the dispenser when the container appears to be full. Automated dispensers include, for example, plastic peanut dispensers often associated with an air delivery system, air bag machines and paper dunnage converters.
A common tendency is for the operator to overfill the container, with the result that more dunnage material may have been placed in the container than was needed adequately to protect the object or objects packed in the container. In other instances, the operator may put too little dunnage material in the container with the result that the object or objects packed in the container can be damaged during shipment. Over-filling and under-filling typically becomes more of a problem as the speed of the dispenser increases. Today, there are void-fill dispensers, in particular paper dunnage converters, that can deliver a strip of dunnage material at rates in excess of 50 feet per minute (about 0.25 meters per second).
A basic solution for the aforesaid problem is disclosed in U.S. Pat. No. 5,871,429. The '429 patent discloses a packaging system comprising a probe for sensing the void in a container and a dunnage converter having a controller for controlling the feeding and cutting of a strip of dunnage material such that there is produced the amount of dunnage material needed to fill the void in the container. As mentioned in the '429 patent, a mechanical probe may be used to probe a container in one or more locations to determine the amount of dunnage material needed to fill the void. The mechanical probe may also be used in conjunction with a bar code reader or used in conjunction with or supplanted by sensors which sense the dimensions or degree of fill of the container, including optical and ultrasonic sensors.
While the above-described system of the '429 patent represents a major advance in the art, a need still exists for improved devices and methods for implementing the basic solution taught in the '429 patent.